Acceleration-sensitive fluid actuator



y 1969 R. w. WARREN 3,444,814

ACCELERATION-SENSITIVE FLUID ACTUATOR Filed Feb. 23, 1967 Sheet of 2 RAMAHZ \O\ FlG.l

y 0, 1969 R. w. WARREN 3,444,814

ACCELERATION-SENSITIVE FLUID ACTUATOR Filed Feb. 25, 1967 Sheet 2 of 2ATM/ME Y:

3,444,814 ACCELERATION-SENSITIVE FLUID ACTUATOR Raymond W. Warren,McLean, Va., assignor to the United States of America as represented bythe Secretary of the Army Filed Feb. 23, 1967, Ser. No. 619,125 Int. Cl.F42c 5/00, 15/32 U.S. Cl. 102-81 11 Claims ABSTRACT OF THE DISCLOSUREAcceleration-sensitive control means are placed in an explosiveprojectile and control a pure fluid circuit therein. Depending onwhether the projectile undergoes an acceleration or deacceleration the.acceleration sensitive control means will direct the pure fluid circuitto either arm or disarm the projectile.

This invention relates to the arming of an ordnance device and inparticular to a pure fluid arming system.

Explosive projectiles are intended to damage a designated target inresponse to a target orientated firing influence. A. firing influencemay be produced by impact, by a proximity sensing device, or by a timingdevice. Maximum effectiveness and maximum safety for the personnel wholaunch the projectile require the use of a highly effective safety andarming device. When the projectile is in the safe, or unarmed, state itcan be handled safely as it is immune to detonation by the accidentalreceipt of a firing influence. When the projectile is in the armed stateit is ready to detonate in response to a firing influence. The safetyand arming device must dependably keep the projectile unarmed until ithas traveled a safe distance after being launched to protect thelaunching crew, if the projectile should accidentally receive a firinginfluence, and must dependably arm the projectile by the time theprojectile receives a target orientated firing influence.

A particular arming situation arises in what is called for convenience adual acceleration explosive projectile. A dual acceleration projectilereceives an initial or primary acceleration upon launching. Theprojectile is designed so, if desired, a secondary acceleration may beapplied to it to increase the range of the projectile beyond that it iscapable of achieving from a primary acceleration alone.

A special problem arises, which the present invention is partlyconcerned with, when a dual acceleration projectile is fired at an enemytarget located between the launching means and friendly troops(hereinafter called a near target) and also when the enemy target islocated a certain distance on the side of friendly troops away from thelaunching means (hereinafter is called a far target). In the case of anear target, because of its closeness to the launching means, theprojectile will be programmed to receive only a primary accelerationwith the result that the arming of the projectile must occur shortlyafter launching, yet at a suflicient distance from the launching crew toinsure their safety upon accidental receipt of a firing influence. It asecondary acceleration is accidentally applied to a projectile that isaimed at a near target, the projectile will pass over friendly troopsand therefore must, upon receipt of a secondary acceleration, bedisarmed to insure against harm to the friendly 3,444,814 Patented May20, 1969 ice troops. If the projectile is aimed .at a far target it willpass over friendly troops with the aid of a secondary acceleration onits path to its designated target. Safety of the friendly troopsrequires that the projectile be maintained in an unarmed state until itsafely passes over the friendly troops to protect them againstaccidental receipt of a firing influence.

It is therefore an object of the present invention to provide aneffective safety and arming system for a dual acceleration explosiveprojectile.

Another object of the present invention is to provide means to arm adual acceleration projectile that is programmed to receive a primaryacceleration to land at a near target as it approaches the target and todisarm the projectile if it should accidentally receive a secondaryacceleration passing it over friendly troops.

A further object of the present invention is to provide a dualacceleration projectile that is programmed for a far target, by use of asecondary acceleration boost, with means to maintain it in an unarmedcondition until it is close to the far target and away from friendlytroops over which it must pass on the way to the far target.

A secondary object of this invention is to provide an effective safetyand arming means for a single acceleration projectile.

Briefly, in one embodiment of the present invention, accelerationresponsive means selectively direct a power source for a bistableamplifier to one of two output conduits. One output conduit is connectedto one side of an arming mechanism while the other output conduit isconnected to various fluid logic elements which allow the projectile tobe armed during preselective portions of flight. A four-way two positionvalve in position cooperates with the fluid logic elements to allow theprojectile to be armed .as it approaches a near target Without the aidof a secondary boost. In this position the projectile will remainunarmed if accidentally subjected to secondary boost. In a secondposition of the valve the projectile will be aimed to land at a fartarget passing over friendly troops with the aid of a secondary boostand Will be armed only in the vicinity of the target.

In second embodiment of the invention an arming device is connected tothe output conduits of an acceleration controlled bistable amplifier toallow the projectile to be armed as it approaches the target anddisarmed as it is launched. In this embodiment of the invention theprojectile does not receive a secondary boost.

The specific nature of the invention, as well as other objects, uses,and advantages thereof, clearly appear from the following descriptionand from the accompanying drawings in which:

FIGURE 1 is a schematic illustration of one embodiment of the presentinvention.

FIGURE 2 is a view of an element used in the embodiment of the inventionas shown in FIGURE 1.

FIGURE 3 is a schematic illustration of a second embodiment of thepresent invention.

In FIGURE 1 an acceleration sensitive fluid actuator is placed in thenose of a projectile 75 with a conduit 101 adapted to receive the ramair of the projectile. Conduit 101 communicates with a bistableamplifier 190 which has an interaction chamber 106. A left controlnozzle communicates left control line 102 with interaction chamber 106.Left control line 102 has a right angle bend which serves to define aconduit section 121 of the line. A seismic mass 105 is positioned tocover the open end of conduit section 121 for purposes which will soonbecome apparent. The seismic mass 105 is, in the absence of accelerationforces, held in a covering position with respect to the open end of theconduit section 121 by flat leaf springs 125 which are attached to eachside of the seismic mass. A right control nozzle 116, a right control103, .a conduit section 129, a seismic mass 104 and flat leaf springs130 are similarly positioned with respect to the right side of thebistable amplifier 190. Bleeds 107 and 108 communicate with interactionchamber 106 in a manner well known in the art. The interior 400 ofprojectile 75 communicates with ambient.

Bistable amplifier 190 has output conduits 109 and 110 of which conduit110 leads to a flow divider 111. The flow divider divides the flowbetween conduits 112 and 113. Conduit 113 leads to an AND element 134.One AND element that might be employed is described in FIGURE 2 of myUS. Patent No. 3,221,990 for a pure fluid shift register. AND element134 has conduits 135 and 136 leading to atmosphere and a conduit 137adapted to direct fluid to the left side 139 of a slider 138. A conduit109 directs fluid to the right side of the slider. The slider is anywell known sliding element such as a piston and reciprocates in acylinder 141. Slider 138 carries a detonator 142 and a firing in 143 islocated above cylinder 141. Conduit 112 leads to a fluid pulse converter150 which could be constructed in accordance with principles set forthin US. Patent No. 3,001,698 for a Fluid Pulse Converter. Pulse converter150 is biased to discharge to conduit 158 initially by offsettingsplitter 300, curving the power jet or any of the well known techniquesin the art.

Pulse converter 150 has feedback legs 151 and 152 which lead to aninteraction chamber 156. A source of pressure 155 communicates withinter-action chamber 156 as do bleeds 153 and 154. Output conduits 157and 158 selectively receive the fluid from interaction chamber 156 andlead to a four-way two position valve 160. Four-way two position valve160 could be any of the well known two position valves that areavailable to the skilled mechanic. In position I, which is schematicallyillustrated in FIGURE 1, conduits 157 and 158 communicate with conduits161 and 159, respectively. In position II, which is schematicallyillustrated in FIGURE 2, the connections are reversed so that conduits157 and 158 communicate with conduits 159 and 161, respectively. Conduit161 leads to AND element 134 while conduit 159 communicates with theright side of slider 138.

In operation, valve 160 is set in accordance with whether the projectileis aimed at a near target or a far target. If the target is a neartarget valve 160 is switched to position I while if the target is a fartarget valve 160 is then at position 11. Assuming projectile 75 is aimeda near target valve 160 will be in position I with conduits 157 and 158communicating with conduits 161 and 159, respectively. Thus asprojectile 75 starts to accelerate in the direction indicated by arrow76, seismic mass 104 will block the end of conduit section 129 of fluidcontrol line 103. Seismic mass 105 will tend to move away from the endof section 121 of left control line 102 allowing the end of section 121to communicate with atmosphere. The ram air from conduit 101 will nowattach to the right side of interaction chamber 106 and be directed toconduit 109. The ram air, as it flows past nozzles 115 and 116, willtend to entrain fluid in the vicinity of these nozzles. Since nozzle 115is communicated to atmosphere, as seismic mass 105 is not covering theend of conduit section 121, ambient air prevents a low pressure regionin the vicinity of nozzle 115. Seismic mass 104 will be covering the endof section 129 because of the acceleration forces received by theseismic mass so that the fluid entrained by the ram air in the region ofnozzle 116 cannot be replaced by ambient air creating a low pressureregion in the area of nozzle 116. The ram air will be drawn to the sideof the interaction chamher in which nozzle 116 is because of the lowpressure there and will be directed to conduit 109 from where it will goto cylinder 141 moving slider 138 to left side of the cylinder. Thiswill maintain the projectile disarmed since detonator 142 is not alignedwith firing pin 143. Fluid from source 155 will be directed to conduit158, because of the bias in pulse converter 150, and through valve 160to conduit 159 to the right side of cylinder 141 to aid in disarming theprojectile. When the initial effects of the primary boost are dissipatedthe projectile will decelerate with seismic mass 104 tending to remainin motion in the direction of the projectile and uncover the end ofsection 129 and opening right control line 103 to ambient. Seismic mass105 will similarly tend to remain in motion in the direction of theprojectile and will move to cover the open end of section 121 of leftcontrol line 102. This will create a low pressure region in the vicinityof nozzle which will switch the ram air to conduit 110 from conduit 109.The fluid in conduit 110 will be directed to conduits 112 and 113. Thefluid from conduit 113 will go to AND element 134 while fluid fromconduit 112 will enter leg 151 of pulse converter where it will directpower fluid from source to output conduit 157. The fluid from conduit112 will enter leg 151 because leg 151 will be at a lower pressure thanleg 152 for the following reason. The fluid from source 155 issuing fromconduit 158 passes adjacent the section of leg 151 near interactionchamber 156 creating a low pressure region in the leg. Thus, a fluidsignal directed to pulse converter 150 will enter leg 151 as it will beat a lower pressure than leg 152. The power fluid leaving conduit 157,by conduit 161, will go to AND element 134 where it will be directed toconduit 137 since conduit 113 will also direct fluid through the ANDelement. As will be recalled, an AND element will direct fluid through aselected output conduit when it receives two fluid signals. The fluid inconduit 137 will move slider 138 to the right side of the cylinder 141aligning firing pin 143 and detonator 142 arming the projectile. Theprojectile is now armed to detonate as it approaches a near target. Ifby accident a secondary thrust is applied to the projectile, it isnecessary to have projectile disarmed as it will now be passing overfriendly troops. When the projectile receives the secondary thrust itwill undergo an ac celeration. As previously pointed out, seismic mass104 will cover the end of conduit section 129 and seismic mass 105 willuncover the end of conduit section 121. This will create a low pressureregion in the vicinity of nozzle 116 switching the ram air from conduit110 to conduit 109 from where the ram air will be transferred to theright side of slider 138 moving the slider to a disarmed position. Pulseconverter 150 will continue to direct fluid to conduit 157 and toconduit 161 to AND element 134 from where the fluid will be dischargedto atmosphere as no signal will be applied to AND element conduit 113.After the secondary acceleration, the projectile will decelerate whenthe effects of the secondary boost dissipates. Since the projectile maystill be over friendly troops it is necessary for the projectile to bedisarmed. Upon deceleration of the projectile seismic mass 104 willuncover the end of conduit section 129 while seismic mass 105 will coverthe end of conduit 121. This will be create a low pressure region in thevicinity of nozzle 115 switching the ram air from conduit 109 to conduit110 from where the fluid will be directed to conduits 112 and 113. Thefluid from conduit 113 will be directed to AND element 134. The fluidfrom conduit 112 will enter leg 152 of pulse converter 150, for thereasons previously explained, switching the power fluid from conduit 157to conduit 153. The fluid from conduit 113 will be vented by AND element134 since no signal will be received by conduit 161 as the pulseconverter will be discharging from conduit 158 and from there to conduit159. Fluid from conduit 159 will be directed to the right side of slider138 to combine with the fluid from conduit 109 to aid in maintaining theprojectile disarrned. Thus, it can be seen that a projectile aimed todetonate at a near target will be armed if no secondary thrust isapplied to the projectile, and, if by accident a secondary thrust isapplied to the projectile passing it over friendly troops, theprojectile will be disarrned eliminating any danger to the friendlytroops.

In valve position II it is intended that the projectile be fired overfriendly troops at a far target by subjecting the projectile to asecondary thrust. It is therefore imperative that the projectile bedisarrned while it passes over friendly troops to eliminate any dangerto the friendly troops from a premature explosion. To insure this, valve160 is set to connect conduit 157 with conduit 159 and conduit 158 withconduit 161. Upon an initial acceleration applied to the projectile,seismic mass 104 will cover end of conduit section 129 and seismic mass105 will uncover the end of conduit section 121. This will create a lowpressure region in the vicinity of nozzle 116 directing ram air toconduit 109 moving slider 138 to the left maintaining the projectiledisarrned. Pulse converter 150 will discharge to conduit 158, because ofits built in bias from where the fluid will be directed to conduit 161and to AND element 134 from where it will discharge to atmosphere as nosignal will be applied to the AND element from conduit 113 since thebistable amplifier will discharge to conduit 109. On deceleration of theprojectile the ram air will be switched to conduit 110 as previouslyexplained. Fluid from conduit 110 will divide to conduits 112 and 113.The fluid in conduit 112 will enter leg 151 of pulse converter 150 forthe reasons previously given. This will switch the power fluid fromconduit 158 to conduit 157 and to conduit 159 where it will be directedto the right side of slider 138 maintaining the slider in a disarrnedposition. The fluid from conduit 113 will be discharged to atmosphere byconduit 135 of AND element 134 since only one fluid signal is applied tothe AND element. When the secondary boost is applied to the projectileseismic mass 104 will cover the end of conduit section 129 while seismicmass 105 will uncover the end of conduit section 121 switching the ramair from conduit 110 to conduit 109. The fluid in conduit 109 with thefluid from conduit 159 will act on slider 138 to maintain the slider inthe left portion of cylinder 141 which corresponds to a disarrnedposition of the projectile. Pulse converter 150 will continue todischarge to conduit 159 as no signal will be received by the pulseconverter. After the secondary boost and the accompanying accelerationthat goes with it dissipates the projectile will undergo a decelerationas it approaches the target area. This will cause seismic mass 104 touncover the end of conduit section 129 and seismic mass 105 to cover theend of conduit section 121 which will switch the ram air to conduit 109to conduit 110. Conduit 110 will direct fluid to conduits 112 and 113.The fluid from conduit 112 will enter leg 152 of pulse converter 150,for reasons previously explained, which will switch the power fluid fromconduit 157 to conduit 158 which communicates with AND element 134 byconduit 161. As conduit 113 is also directing fluid to the AND element,the latter will discharge fluid to conduit 137 which will move slider138 to the right of cylinder 141 which corresponds to an armed positionof the projectile. Thus, it can be seen that the projectile will bearmed as it approaches the target with the aid of a secondary boost anddisarrned in the vicinity of friendly troops over which it passes. It isalso apparent that if the projectile does not receive a secondary boostit will be in a disarrned position while it is over the friendly troopsand if it should land among the friendly troops detonation will notoccur.

FIGURE 3 is the same as FIGURE 1 with respect to the seismic masses andthe bistable amplifiers and like elements are identically numbered.However, output conduits 109 and 110 of bistable amplifier 190 directlycommunicate with slider 138. The acceleration sensitive fluid actuatorof FIGURE 3 is intended to disarm projectile 75 without regard to thelocation of friendly troops with respect to the target location andwithout any consideration to a possible secondary boost applied thereto.When the projectile is accelerated during launching the seismic massesof FIGURE 3 will act identical to those of FIG- URE 1 in covering theend of conduit section 129 and uncovering the end of section 121. Aswill be recalled this will direct ram air to conduit 109 which willdisarm the projectile. When the projectile undergoes deceleration as theprimary boost dissipates the seismic masses will cover the end ofconduit section 121 and undercover the end of conduit section 129 whichwill switch the ram air to conduit which will arm the system. Thus itcan be seen the projectile will be disarrned while it is launched andarmed as it decelerates approaching the target.

It is thus apparent that I have invented a novel and flexible armingsystem that can be used in a dual or single acceleration arming system.Obviously instead of aligning a firing pin and detonator a fluidactivated switch in projectile 75 could be activated to complete anarming circuit.

I claim as my invention:

1. An acceleration-sensitive fluid arming device comprising:

(a) a projectile,

(b) means in said projectile to maintain said projectile disarrned uponan initial acceleration applied to said projectile,

(c) means in said projectile to arm said projectile upon said projectilebeing subjected to an initial deceleration,

(d) means in said projectile to again disarm said projectile upon asecond acceleration applied to said projectile, and

(e) means in said projectile to keep said projectile disarmed when saidprojectile is subjected to a second deceleration.

2. An acceleration-sensitive arming device comprising:

(a) a projectile,

(b) a bistable fluid amplifier in said projectile having a power sourceand two output conduits,

(c) acceleration-sensitive means to selectively direct saii power sourceto either of said output conduits, an

(d) arming means controlled by said output conduits to arm saidprojectile.

3. A device according to claim 2 wherein:

(a) said bistable amplifier has a plurality of control conduits, eachhaving an open end to selectively control said power source to saidoutput conduits,

(b) said acceleration sensitive means includes means to cover said openends of said control conduits.

4. A device according to claim 3 wherein said acceleration-sensitivemeans comprise seismic masses.

5. A device according to claim 4 wherein said arming means comprises:

(a) a detonator carried by a slider, and

(b) a firing mechanism positioned above said slider.

6. A device according to claim 5 wherein said power source comprises theram air of said projectile.

7. A device according to claim 2 wherein said arming means comprises:

(a) a cylinder having two sides and at least one port in each side,

(b) a slider housed in said cylinder,

(0) a detonator carried by said slider,

(d) a firing mechanism positioned above said slider,

and

(e) one of said output conduits communicates with one of said ports onone side of said cylinder.

8. A device according to claim 7 wherein:

(a) an AND element communicates with said other of said output conduits,and

7 8 (b) said AND element further communicates with one References Citedof said ports in said other side of said cylinder. UNITED STATES PATENTS9. A device according to claim 8 wherein: (a) a pulse converter havingtwo output conduits com- 1850196 3/1932 Bardsley 102 81 rnunicates withsaid other of said output conduits, 5 3,229,638 1/1966 Woolston et 10281 X (b) a four way valve communicates with said output 3,237,712 3/1966Horton 181 -5 conduits of said pulse converter, (c) said four way valvefurther communicates with SAMUEL FEINBERG Exammersaid AND element andsaid one side of said cylinder. G, H. GLANZMAN, Assistant Examiner. 10.A device according to claim 8 wherein said pulse 10 converter is biasedto one of its output conduits.

11. A device according to claim 10 wherein said four 13781.5 way valveis a two position valve.

US. Cl. X.R.

